STENOTREMA. 297 



Triodopsis hirsitta, WOODWARD, Man., PI. XII. Fig. 7, no desc. 



Helix fraterna, WOOD, Index, Suppl. 21, PI. VIII. Fig. 16 (1828); ed. HANLEY, 



126, Fig. 16. 

 ? Helix portina, SAY, Long's Exped. (1824), II. 257, PI. XV. Fig. 2 (young) ; 



BIXN-EY'S ed., 30, PL LXXIV. Fig. 2. DF.KAY, N. Y. Moll., 45(1843).- 



PFEIFFER, Mon: Hel. Viv., III. 97. BLAND, Ann. N. Y. Lye., VI. 344, 



with fig. (1858). 

 Stenotrema hirsuta, TRYON, Am. Journ. Conch., III. 57 (1867). 



Animal whitish; head, eye-peduncles, and tentacles slate-color; foot slender, 

 semi-transparent; length less than twice the diameter of the shell, terminating 

 acutely. Cavity of the eye-peduncles apparent, when they are retracted, by 

 two dark lines with a white space between. 



A post-Pleiocene species, now found over the Northern and Interior regions 

 as far as Kansas and Virginia, and even into Alabama. 



The last whorl in front of the aperture, especially in the larger forms, is more 

 or less angulated, but never carinated. The position of the parietal tooth is 

 often rather oblique, but usually nearly parallel with the peristome, and is more 

 or less distant from it. The nature of the epidermis varies ; in some forms the 

 hairs are very numerous, in others comparatively few. Spiral impressed lines 

 sometimes occur beneath the epidermis, at the base of the shell. 



Jaw as usual ; 8 crowded, broad ribs. 



Lingual membrane (PI. VII. Fig. F) has 221 22 teeth; 10 perfect 

 laterals. 



Anatomy figured by Leidy (1. c.). Genitalia (Fig. 5). Penis sac long, cylin- 

 drical, blunt above, where it receives retractor muscle and vas deferens ; geni- 

 tal bladder narrow, elongate-ovate, on a short, narrow duct ; the convolution in 

 the epididymis commences near the testicle. 



Stenotrema maxillatum, GOULD. 

 Vol. III. PI. XL. a, Fig. 2. 



Shell imperforate, globose-conic, rather solid, completely covered with short 

 hairs, chestnut-colore'd ; spire convex-conoid, apex obtuse ; whorls 5, rather 

 convex, gradually increasing, the last anteriorly deflected, constricted, subin- 

 flated below; aperture oblique, linear, almost closed by a broad, jaw-shaped 

 denticle within the peristome ; peristome thickened, its terminations joined by 

 a stout, erect parietal callus, the right margin subrectilinear, arched, angularly 

 merging into the very heavy basal margin ; within the base of the shell is a 

 transverse tubercle. Greater diameter 7, lesser 6 mill. ; height, 5 mill. 



Helix maxillata, GOULD, Proc. Bost. Soc., III. 38 ; in Terr. Moll., II. 157, PI. 



XL. a, Fig. 2. PFEJFFEU, Mon. Hel. Viv., III. 126 ; IV. 164. W. G. BIN. 



KEY, Terr. Moll., IV. 65; L. & Fr.-W. Sh., I. 119 (1869). 

 Stenotrema maxillata, TKYON, Am. Journ. Conch., III. 57 (1867). 



